Magnetization Measurements in Y-Ba-Cu-O Compound System

Magnetization measurements for (Y 0.5 Ba 0.5 )CuO 3- y compound at 77 K and 4.2 K indicated that the material was type II superconductor. Critical current densities at 1 T derived from magnetization curves were 13 A/cm 2 at 77 K and 3×10 3 A/cm 2 at 4.2 K. Upper critical field H c2 (mid-point) at 77 K was 15 T. Several parameters such as H c2 at 0 K, H c , ζ GL , λ GL and κ were estimated.